X-rays still remain the most widely used primary investigation for query pneumothorax. In recent years, ultrasound has become increasingly popular for this question in ICU’s around the world... but what is better? This article conducted a meta-analysis including 13 studies from 2002-2012. They were able to show that pleural ultrasound is more sensitive indeed compared to chest radiography in detecting a pneumothorax. It is interesting to note, that most studies were related to trauma patients and only one was conducted by intensivists. Maybe it’s because verifying catheter positions with normal ultrasound remains challenging.
A nice tutorial can be found here: Tutorial Ultrasound for pneumothorax
Saadah A, et al. Critical Care, November 2013. Provisional article, in print